A living creature could be infected by a disease in a number of ways, such as coming into contact with another infected creature, touching diseased matter, consuming food or drink tainted with disease, or being the victim of a biological weapon attack. All living creatures had an immune system that was able to fight off infection which could lead to recovery. However, in severe cases medical treatment was required.[4]

If left untreated, a disease could wreak havoc on a being. Depending on the type and severity, diseases could bring about unconsciousness, the loss of a limb, or death.